Balanced pair cable has higher attenuation at higher frequencies, hence the longer the wire between DSLAM and subscriber, the slower the maximum possible data rate. The following is a rough guide to the relation between wire distance and maximum data rate. Local conditions may vary, especially beyond 2 km, often necessitating a closer DSLAM to bring acceptable speeds:

     Speed Mbit/s      Distance (km)
     25      0.30
     24      0.6
     23      0.9
     22      1.2
     21      1.5
     19      1.8
     16      2.1
     1.5      4.5
     0.8      5.2